Java LeetCode 78. Subset

Given a set of integer arrays nums without repeated elements, return all possible subsets (power sets) of the array.
Note: The solution set cannot contain duplicate subsets.
Example:
Input: nums = [1,2,3]
Output:
[
[3],
[1],
[2],
[1,2,3],
[1,3],
[2,3],
[1 ,2],
[]
]

class Solution {
    
    
    public List<List<Integer>> subsets(int[] nums) {
    
    
        List<List<Integer>> res = new ArrayList();
        Deque<Integer> que = new LinkedList();
       
        back(0,nums,que,res);
        return res;
    }
    public void back(int start,int[] nums,Deque<Integer> que,List<List<Integer>> res){
    
    
        
        res.add(new ArrayList(que));
            
        

        for(int i=start;i<nums.length;i++){
    
    
            que.addLast(nums[i]);
           
            back(i+1,nums,que,res);
            
            que.removeLast();
        }
    }
}